Field of Invention
The present disclosure relates to power converting technology. More particularly, the present disclosure relates to a power converter.
Description of Related Art
Typically, a current sampling circuit in a switch power supply is directly connected in series to a switch (for example, a metal-oxide-semiconductor field-effect transistor, or MOSFET). However, the current sampling circuit increases the lead inductance of the MOSFET, such that the MOSFET generates a high voltage peak during the switching process. Such a high voltage peak not only generates high frequency noise, but also decreases the efficiency of the switch power supply. Furthermore, if voltage is extremely high, the high voltage may further damage the MOSFET permanently.
Typical ways in which to solve the above-mentioned problems include (1) increasing a gate driving resistance of the MOSFET or connecting a high frequency capacitor at two terminals of the MOSFET in parallel in order to decrease a switching speed of the MOSFET; and (2) using a snubber circuit to absorb a portion of the power of the voltage peak. However, although the peak value of the voltage peak may be reduced using these two methods, the decrease in the switching speed increases the switching loss of the switch power supply, such that the efficiency of the power converter decreases.
In view of the foregoing, problems and disadvantages are associated with existing products that require further improvement. However, those skilled in the art have yet to find a solution.